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As a popular marine saccharide, chitooligosaccharides (COS) has been proven to have good antioxidant activity. Its antioxidant effect is closely related to its degree of polymerization, degree of acetylation and sequence. However, the specific structure–activity relationship remains unclear. In this study, three chitosan dimers with different sequences were obtained by the separation and enzymatic method, and the antioxidant activity of all four chitosan dimers were studied. The effect of COS sequence on its antioxidant activity was revealed for the first time. The amino group at the reducing end plays a vital role in scavenging superoxide radicals and in the reducing power of the chitosan dimer. At the same time, we found that the fully deacetylated chitosan dimer DD showed the strongest DPPH scavenging activity. When the amino groups of the chitosan dimer were acetylated, it showed better activity in scavenging hydroxyl radicals. Research on COS sequences opens up a new path for the study of COS, and is more conducive to the investigation of its mechanism.

We previously demonstrated that 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) promoted the production of nitric oxide (NO) and proinflammatory cytokines by activating the mitogen-activated protein kinases (MAPK) and Janus kinase (JAK)/STAT pathways in RAW 264.7 cells, indicating good immunomodulatory activity of HACC. In this study, to further investigate the immunomodulatory mechanisms of HACC, we determined the roles of phosphatidylinositol 3-kinase (PI3K)/Akt, activating protein (AP-1) and nuclear factor kappa B (NF-κB) in HACC-induced activation of RAW 264.7 cells by the western blotting. The results suggest that HACC promoted the phosphorylation of p85 and Akt. Furthermore, c-Jun and p65 were also increased after the treatment of RAW 264.7 cells with HACC, indicating the translocation of NF-κB and AP-1 from cytoplasm to nucleus. In addition, as scanning electron microscopy (SEM) analysis shows, the cell morphology changed after HACC treatment. These findings indicate that HACC activated MAPK, JAK/STAT, and PI3K/Akt signaling pathways dependent on AP-1 and NF-κB activation in RAW 264.7 cells, ultimately leading to the increase of NO and cytokines.

A new kind of eco-friendly superabsorbent polymer was successfully synthesized using (2-pyridyl) acetyl chitosan chloride (PACS), acrylic acid (AA) and acrylamide (AM) in aqueous solution by a free radical polymerization. The effect of different reaction conditions, such as the initiator content, crosslinker content and PACS content were investigated. And the water retention, salt tolerance and reuse ability were investigated too. The chemical structure and morphological characterizations of the superabsorbent polymer were investigated by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA) and Scanning electron microscope (SEM). The results showed that the novel superabsorbent polymer exhibits excellent water absorbency, which can absorb distilled water 615 g/g and 0.9% NaCl solution 44 g/g. At the same time, this product showed excellent water retention and reusability. The antibacterial properties of the superabsorbent polymers were tested too. The introduction of antibacterial groups also enhances antibacterial properties against Escherichia coli and Staphylococcus aureus. This kind of superabsorbent polymer has a broad application prospect.

Chitosan is widely used as a medical material because of its excellent biological activities. However, the low solubility of natural chitosan limited its medicinal activity to some extent. The solubility can be improved by introducing more active groups and lowering molecular weight. Therefore, 6-amine chitosan derivatives were synthesized in this paper since more active groups were introduced to increase the medicinal activity. Those derivatives were characterized by elemental analysis, HPLC, and FT-IR and the antiviral activity was tested by hemagglutination tests. Finally, 6-amine chitosan derivatives improved the antiviral activity, especially after the introduction of bromine ion. When 6-deoxy-6-bromo-N-phthaloyl chitosan was 1 g/L, they reduced the hemagglutination titer of virus to zero. The RT-PCR result showed that the expression level of TNF-α and IFN-β increased significantly, which indicated that the antiviral activity of amino-modified chitosan worked through the stimulation of immune response.

A gastric cancer angiogenesis marker peptide, GX1, is promising to be a desirable ligand for anti-angiogenesis targeted drug of gastric cancer treatment. In this study, GX1 was utilized to fabricate a multifunctional vascular targeting docetaxel (DCT)-loaded nanoparticle with N-deoxycholic acid glycol chitosan (DGC) as the carrier and GX1-PEG-deoxycholic acid (GPD) conjugate as the targeting ligand. The mean size of obtained GX1-DGC-DCT was 150.9 nm with a narrow size distribution and their shape was spherical with smooth surface texture. The in vitro drug release test revealed a sustained release manner and an acid pH could accelerate the release compared with the neutral pH. Furthermore, GX1-DGC-DCT showed stronger cytotoxicity against co-cultured gastric cancer cells and human umbilical vein endothelial cells (co-HUVEC) than DCT within 100 μM. In addition, GX1 efficiently enhanced the cellular uptake of nanoparticles in co-HUVEC cells as confirmed by confocal fluorescence scanning microscopy. Moreover, in vivo delivery of GX1-DGC-DCT was demonstrated to inhibit tumor growth in SGC791 tumor-bearing mice with tumor inhibition rate (TIR) of 67.05% and no weight loss of mice was observed. The anti-tumor effects were further confirmed by H&E and TUNEL analysis. Therefore, this new drug delivery system represents a potential strategy for gastric cancer therapy.

The giant jellyfish, Nemopilema nomurai, is widely distributed from the Eastern China Sea to the northern part of the Yellow Sea and has resulted in numerous hospitalizations in coastal areas of China, especially in Northern China. Our previous studies have revealed sting-related proteins in the venom of the jellyfish N. nomurai by using experimental and omics-based approaches; however, the variable symptoms of patients who have been stung by N. nomurai are not fully understood. This limited knowledge led to an examination of whether intraspecific variations occur in the venom of different N. nomurai. In the present study, 13 specimens of N. nomurai were collected from the Yellow Sea, and their venom was characterized by profiling differences in biochemical properties and biological activities. SDS-PAGE analysis presented recognizable differences in the number, intensity and presence of some protein bands. Moreover, enzymatic assays revealed considerable quantitative variations in metalloproteinase activity and PLA2-like activity. In particular, zymography assays of proteases demonstrated the general presence of abundant metalloproteinases in jellyfish nematocyst venom; however, the catalytic activities varied greatly among some specific metalloproteinases in the 28–46 kDa or 57–83 kDa range. Hemolytic assays using sheep erythrocytes suggested a predominant variance in the toxicities of different individual jellyfish venoms, with the difference between the most hemolytic and the least hemolytic venom as large as 77-fold. The current data suggested remarkable variations in the nematocyst venoms of individual N. nomurai jellyfish. These observations will provide a new understanding of the clinical manifestations induced by N. nomurai jellyfish stings and will therefore have important implications for preventing and treating jellyfish envenomations.

Introduction: Docetaxel (DTX) is one of the most important chemotherapeutic agents and has been widely used for treatment of various types of cancers. However, the clinical chemotherapy of DTX give...

Context: Compounds to treat hypothyroidism in the absence of cardiac side effects are urgently required. In this regard, γ-aminobutyric acid (GABA) has gained interest due to its anti-anxiolytic, antihypertensive and antioxidant properties, and reported benefits to the thyroid system. Objective: We investigated the ability of GABA to ameliorate fluoride-induced thyroid injury in mice, and investigated the mechanism(s) associated with GABA-induced protection. Materials and methods: Adult male Kumning mice (N = 90) were exposed to NaF (50 mg/kg) for 30 days as a model of hypothyroidism. To evaluate the effects of GABA administration, fluoride-exposed mice received either thyroid tablets, or low (25 mg/kg), medium (50 mg/kg) or high (75 mg/kg) concentrations of pure GABA orally for 14 days groups (N = 10 each). The effects of low (50 mg/kg); medium (75 mg/kg) and high (100 mg/kg) concentrations of laboratory-separated GABA were assessed for comparison. Effects on thyroid hormone production, oxidative stress, thyroid function-associated genes, and side-effects during therapy were measured. Results: GABA supplementation in fluoride-exposed mice significantly increased the expression of thyroid TG, TPO, and NIS (P

Jellyfish are rich in resources and widely distributed along coastal areas. As a potential approach to respond to jellyfish blooms, the use of jellyfish-derived products is increasing. The citrus spider mite (Panonychus citri) is one of the key citrus pests, negatively impacting the quality and quantity of oranges. Due to the resistance and residue of chemical acaricides, it is important to seek natural substitutes that are environmentally friendly. The field efficacy of the venom from the jellyfish Nemopilema nomurai against P. citri was assayed in a citrus garden. The frozen N. nomurai tentacles were sonicated in different buffers to isolate the venom. The venom isolated by PBS buffer (10 mM, pH 6.0) had the strongest acaricidal activity of the four samples, and the corrected field efficacy 7 days after treatment was up to 95.21%. This study demonstrated that jellyfish has potential use in agriculture.

Damage to the cell membrane is an effective method to prevent drug resistance in plant fungal diseases. Here, we proposed a negative remodeling model of the cell membrane structure induced by the C-coordinated O-carboxymethyl chitosan Cu (II) complex (O-CSLn-Cu). FITC-labeled O-CSLn-Cu (FITC-O-CSLn-Cu) was first synthesized via a nucleophilic substitution reaction and confirmed by FT-IR. FITC-labeled O-CSLn-Cu could pass through the fungal cell membrane, as detected by confocal laser scanning microscopy (CLSM) coupled with fluorescein isothiocyanate (FITC)-fluorescence. O-CSLn-Cu treatment led to apparent morphological changes in the membranes of P. capsici Leonian and giant unilamellar vesicles (GUVs) by transmission electron microscopy (TEM). Then, we performed component analysis of the cell membrane from the P. capsici Leonian affected by O-CSLn-Cu with a particular interest in membrane physicochemical properties. Many unsaturated fatty acids (UFAs) and key enzymes promoting UFA synthesis of the cell membrane were downregulated. Similarly, a large number of membrane proteins responsible for substance transport and biochemical reactions were downregulated. Furthermore, O-CSLn-Cu treatments increased plasma membrane permeability with significant leakage of intercellular electrolytes, soluble proteins and sugars, and lipid peroxidation with decreasing membrane fluidity. Finally, aquaporin 10 was proven to be a potential molecular target sensitive to antimicrobial agents according to composition analysis of membrane structure and immunohistochemistry.

Oyster (Crassostrea talienwhanensis) protein was hydrolyzed by trypsin to produce peptides with different response values, and response surface methodology (RSM) was applied to optimize the hydrolysis conditions. The highest degree of hydrolysis (DH) of the oyster peptide (OP) was obtained at an enzyme concentration of 1593.2 U/g, a pH of 8.2, a hydrolysis temperature of 40.1 °C, a hydrolysis time of 6.0 h, and a water/material ratio of 8.2. The greatest hydroxyl-radical-scavenging activity of OP was obtained at an enzyme concentration of 1546.3 U/g, a pH of 9.0, a hydrolysis temperature of 50.2 °C, a hydrolysis time of 5.1 h, and a water/material ratio of 5.6. The largest branched-chain amino acid (BCAA) content of OP was obtained at an enzyme concentration of 1323.8 U/g, a pH of 8.3, a hydrolysis temperature of 41.7 °C, a hydrolysis time of 6.7 h, and a water/material ratio of 4.8. The three experimental values were significantly in agreement with the predicted values within the 95% confidence interval. Furthermore, ultrafiltration and chromatographic methods were used to purify the OP, and 13 peptides that were rich in Lys, Arg, His, and Thr were identified by LC-MS/MS. The results of this study offer different optimum hydrolysis conditions to produce target peptides from oyster protein by using RSM, and this study provide a theoretical basis for the high-value utilization of oyster protein.

In this study, we synthesized negatively charged chitosan sulfate and positively charged hydroxypropyltrimethyl ammonium chloride chitosan (HACC), and then prepared chitosan derivatives with positive and negative ions as nanoparticles (NPs) by ovalbumin encapsulation using the polyelectrolyte method. NPs with different substitution sites and molecular weights (MW) were prepared by varying conditions. We then determined the zeta potential average, diameter, encapsulation effect, and their immunostimulatory effects on dendritic cells (DCs). The results showed that chitosan-derivative NPs ranged in size from 153.33 to 320.90 nm; all NPs were positive, with charges ranging from 17.10 to 39.30 mV and the encapsulation rates of 65 %-75 %. Three NPs greatly promoted the expression and secretion of interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and interleukin-1β (IL-1β) in DC cells: C2,3,6 chitosan sulfate-HACC (C2,3,6-HACC; 200 kDa), C3,6 chitosan sulfate-HACC (C3,6-HACC; 200 kDa) and C6 chitosan sulfate-HACC (C6-HACC; 50 kDa). We also found that 200-kDa C2,3,6-HACC and 50-kDa C6-HACC NPs greatly increased secretion of the major histocompatibility complex-II (MHC-II), CD40, CD80, and CD86, indicating that these NPs promote effective antigen presentation, further increasing immunity effects. Finally, we applied laser confocal photography and determined that NPs entered the cell to promote the regulation of cellular immune activity; this discovery lays a foundation for further research on their mechanism of their action. Therefore, C2,3,6-HACC and C6-HACC NPs have the potential as immunological adjuvants.

Background: The Intervention effect of fucoxanthin, which is reportedly a powerful antioxidant, on cadmium-induced thyroid damage in mice was evaluated.Methods: Animals (N = 120) were divided into control group (given pure water, N=20) and CdCl-exposed group (given CdCl orally at a dose of 30 mg/kg body weight (bw)/day for 30 days, N=100). Besides, the CdCl-exposed group were divided into following 5 groups (N=20) to evaluate the intervention effect of fucoxanthin: 1) negative control group (NCG, animals were supplied with pure water); 2) positive control group (PCG, animals were supplied with 50 mg/kg bw/day thyroid tablets); 3) low fucoxanthin concentration group (F1, animals were supplied with 10 mg/kg bw/day fucoxanthin); 4)medium fucoxanthin concentration group (F2, animals were supplied with 25 mg/kg bw/day fucoxanthin); 5) high fucoxanthin concentration groups (F3, animals were supplied with 50 mg/kg bw/day fucoxanthin). A 14-day treatment was conducted for these animals. The levels of T4, T3, MDA, APX and CAT were measured, and the expression levels of Bax, Bcl-2, ERK1, ERK2, MEK1, eIf2α, p-eIf2α, GRP78 and GRP94 genes were determined using real-time reverse transcriptase-polymerase chain reactions (RT-PCR). In addition, tissue histopathology and ultrastructure were recorded and analyzed.Results: We found that injection of cadmium chloride (CdCl) decreased blood T4 and T3 levels to 27.10 ng/ml and 837.74 pg/ml, respectively. In addition, CdCl intoxication induced oxidative stress, structural abnormalities and apoptosis in thyroid follicles. Our results showed that treatment of CaCl-exposed mice with 25-50 mg/kg bw/day fucoxanthin appreciably decreased oxidative stress and apoptosis induced by CdCl, and restored the microstructural and ultrastructural organisation of the thyroid gland towards normalcy. Compared with the negative control group, fucoxanthin treatment groups showed significantly upregulated T4 and T3 levels (52.17 ng/ml and 1669.18 ng/ml, respectively; P ＜ 0.05), relieved oxidative stress by decreasing Malondialdehyde (MDA) level and increasing Catalase (CAT) and Ascorbate Peroxidase (APX) levels, and increased apoptosis inhibition through inhibiting the ERK1/2 pathway and preventing endoplasmic reticulum stress in thyroid follicular epithelial cells.Conclusion: Herein, our study provides evidence of the protective effects of fucoxanthin supplementation against thyroid damage, and suggests therapeutic potential of this pigment in cases of Cd intoxication and hypothyroidism.

Novel Co

The structure modification of chitosan has great application potential. 6-Oxychitosan was prepared by specially oxidizing the C6-OH of chitosan, then 6-oxychitosan was reacted with three kinds of aldehydes to prepare N-quaternized 6-oxychitosan derivatives in this paper. The derivatives were characterized by FT-IR, NMR, and elemental analysis. The antimicrobial activity of these derivatives was tested against two common plant-threatening fungi and three plant disease bacteria. The results showed that N-quaternized 6-oxychitosan derivatives had good water-solubility and excellent antimicrobial activity. Moreover, derivative 3 which connected 8-hydroxyquinolines had the highest antimicrobial activity than the other derivatives. The inhibitory indices of derivative 3 against V. albo-atrum and P. hibernalis are 89.1% and 72.8% at 0.4 mg/ml. The MICs of 3 against X. oryzae, P. syringae, and E. rhapontici were 625, 625, and 156 mg/l, respectively. All the results indicate that derivative 3 has the potential of becoming an alternative to harmful agricultural chemicals.

Botrytis cinerea, Phytophthora capsici Leonian, and Fusarium solani are important plant pathogenic fungi which can cause great crop losses worldwide, but their control methods are limited. It is necessary to develop efficient and green fungicides from abundant marine resources. Chitosan is a non-toxic, biodegradable, biocompatible marine polysaccharide which has prospective applications in agriculture. In this paper, to increase the antifungal activity of chitosan for application, novel water-soluble functional chitosan derivatives were synthesized by grafting polyaminoethyl and diethoxyphosphoryl groups in accordance with a strategy of improving protonation potential. The derivatives were characterized by FTIR, NMR, XRD, SEM, Gaussian 09 and elemental analysis. The antifungal activities against the three fungi and the cytotoxicity were estimated in vitro. The results showed that the derivatives had better antifungal activities and water solubility than chitosan, and had good biocompatibility. They confirmed that these chitosan derivatives can be developed as antifungal agents for plant protection purposes.

Although prebiotic activities of alginate and agar oligosaccharides isolated from seaweeds have been reported, it remains unknown whether seaweed polysaccharides have prebiotic activity. In this study, we isolated polysaccharides from four species of seaweeds, such as Grateloupia filicina (GFP), Eucheuma spinosum (ESP), Ulva pertusa (UPP), and Ascophyllum nodosum (ANP), and characterized their structures and prebiotic effects in vitro. The results showed that these polysaccharides were different in total sugar and sulfate contents as well as monosaccharide composition. GFP and ESP significantly promoted bifidobacterium proliferation and 0.1% ESP and 0.4% GFP resulted in the highest proliferation rates of beneficial bacteria, whereas UPP and ANP inhibited the growth of beneficial bacteria at all tested concentrations (0.1%–0.5%). The different behaviors of the four seaweed-originated polysaccharides might be reflected by differences in monosaccharide composition and structure. Therefore, polysaccharides isolated from GFP and ESP could be utilized as prebiotics. However, more studies must be carried out in vivo.

This study reports the preparation, purification and identification of an antioxidative peptide from mackerel (Pneumatophorus japonicus) protein. Neutrase was chosen as the optimum protease, with the highest cellular antioxidant activity of 53.65%. The optimal hydrolysate conditions for mackerel protein hydrolysates (MPH) according to response surface methodology were an enzyme concentration of 1203.2 U g−1, extraction time of 4.53 h, pH of 7.26, water/material ratio of 5.22 v/w and extraction temperature of 43.72 °C. MPH was separated using ultrafiltration membranes, and the fraction MPH-III with molecular weight below 3500 Da showed the highest cellular antioxidant activity. Five fractions were separated from MPH-III on a Sephadex G-25 column, and MPH-III-2, exhibiting the highest cellular antioxidant activity, was further separated with an XBridge® peptide BEH C18 column. The MPH-III-2-6 separated from RP-HPLC was further analysed by Thermo Scientific Q Exactive mass spectrometer, and the heptapeptide LDIQKEV (843.5 Da) and the octapeptide TAAIVNTA (759.4 Da) were identified. The results of this study offer a promising alternative to produce natural antioxidative peptides from fish protein hydrolysate, which may be utilized as functional ingredients in food systems.

The purpose of this study was to investigate the potential of using dietary supplemental enzymatically hydrolyzed scallop visceral protein (EHSVP) and scallop visceral protein (SV) to replace fishmeal with regard to the growth performance, carcass characteristics, immune response, intestinal microbiota, and intestinal morphology of broiler chickens. A total of 300 1-d-old broiler chickens were randomly assigned to 6 treatments with 5 cages per treatment and 10 broiler chickens per cage. The broiler chickens received a basal diet supplemented with 3% fishmeal or different concentrations of EHSVP (1%, 2%, and 3%) and SV (2% and 3%) treatments until d 42. Broiler chickens fed a diet with 2% EHSVP supplementation exhibited a greater average daily weight gain (P

Oysters (Crassostrea talienwhanensis) contain large amounts of protein and exhibit many biological activities. This study was aimed at preparing oyster protein hydrolysates (OPH) and evaluating the OPH based on a spatial learning and memory capacity. A response surface methodology was employed to optimize hydrolysis conditions to determine the OPH with the highest AChE inhibitory activity, and the optimum extraction conditions were as follows: enzyme concentration of 1444.88 U g−1, pH of 7.38, extraction temperature of 45 °C, extraction time of 5.56 h and a water/material ratio of 2.45 : 1, and the minimum acetylcholinesterase (AChE) activity was 0.069 mM min−1. The spatial memory and learning abilities and passive avoidance in mice were determined by using the Morris water maze test and a dark/light avoidance test. Furthermore, the OPH group could relieve oxidative stress, reduce AChE levels, increase choline acetyltransferase (ChAT) levels and alleviate inflammatory reaction through reduction of interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels. Additionally, up-regulated expressions of brain-derived neurotrophic factor (BDNF) and neural cell adhesion molecules (NCAM) were observed in mice treated with OPH. These findings suggested that OPH could be a functional food candidate to improve the learning and memory ability associated with oxidative stress and inflammatory reactions.

Plant fungal diseases can lead to yield reduction and quality degradation in crops, which usually cause serious economic losses. Additionally, chemical fungicides used in the prevention and control of plant diseases are increasingly restricted due to resistance development and high toxicity. Therefore, biogenic fungicides such as chitosan with low toxicity and good biocompatibility are receiving increasing attention. This study found that the acid swelling chitosan pretreatment method can accelerate the rate of the specific oxidation of chitosan catalyzed by the TEMPO-NaBr-NaOCl system. This study proved that OCTS induces plant disease resistance, and the control efficiencies achieved in protection and treatment experiments against Botrytis cinerea were 80.6 % and 83.4 %, respectively, at 400 μg/mL OCTS. In addition, OCTS can promote plant growth and enhance plant defense enzyme activities. This research has realized a forward-looking exploration of the application of OCTS in the agricultural field.

Vaccines have always been the most effective preventive treatment. Advancements in the field of vaccine is inseparable from adjuvants. Adjuvants are substances added to vaccines to enhance immunogenicity and induce a stronger immune response. Chitosan fascinated considerable attention as vaccine adjuvant due to its unique physicochemical and biological properties. Many studies have shown that chitosan and its derivatives can effectively activate antigen-presenting cells and induce cytokine stimulation to produce an effective immune response and promote the balance of Th1/Th2 response. Among many derivatives, the quaternized chitosan performs better. This review presents the main factors affecting the adjuvant performance of chitosan and quaternized chitosan firstly. Then, we introduced not only the immune response they may cause, but also their metabolic research in detail. Furthermore, their future prospects are forecasted. Overall, chitosan and quaternized chitosan are both promising adjuvant materials, and quaternized chitosan shows greater potential.

Summary Rapana venosa (Rv) is an abundant marine snail resource with high content of protein. The antioxidant activities of Rv meat and visceral mass during simulated gastrointestinal (GI) digestion and their membrane ultrafiltration fractions were evaluated. Results indicated that visceral mass possessed stronger antioxidant activities than meat. The simulated GI digestion increased the hydroxyl radical scavenging activity while decreased the 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power. After membrane ultrafiltration, there were three fractions, that is molecular weight (MW) > 10 kDa, MW 3.5–10 kDa and MW 10 kDa and MW 10 kDa showed the highest reducing power for meat and visceral mass, respectively. Rv hydrolysates exhibited significantly higher hydroxyl radical scavenging activity than the positive control vitamin C (Vc) and may serve as useful ingredients for application in food industry nutritional products.

Cadmium (Cd) is one of the most toxic heavy metals, which is readily taken up by plant roots and has deleterious effects on crop yield and quality. The study investigated the potential cross-protection roles of chitooligosaccharide (COS) in alleviating Cd toxicity in edible rape (Brassica rapa L.) under greenhouse conditions. The results demonstrated that spraying COS onto the leaves of edible rape could promote the plant growth and leaf chlorophyll contents, decrease the malondialdehyde (MDA) level in leaves as well as the Cd2+ concentration in shoots and roots of edible rape under Cd stress. Moreover, exogenous COS could obviously enhance the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POX) in edible rape leaves under Cd-toxicity. The alleviation effect of COS on Cd stress was concentration-dependent and COS of 50–100 mg L−1 showed the best activity. Subcellular distribution experiments further revealed that COS of 50 mg L−1 decreased the proportion of Cd in the organelle fraction of leaves by 40.1% while increased the proportion of Cd in the soluble fraction by 13.2%. These results indicated that COS had a potential to enhance plant resistance to Cd through promoting antioxidant enzyme activities and altering Cd subcellular distribution.

In this study, three different carboxymethyl chitosans (CMCs), namely O-carboxymethyl chitosan (OC), N-carboxymethyl chitosan (NC) and N,O-carboxymethyl chitosan (NOC), were prepared as nano-carriers for an anti-tumor drug, docetaxel (DCT). Three CMCs were fabricated into drug-loading nanoparticles under different preparing conditions respectively. A series of characterization parameters were determined including drug loading capacity (DC), entrapment efficiency (EE), particle size distribution, zeta potential, and morphology, which were used to find the optimized preparing condition for three kinds of nanoparticles (NPs). Furthermore, the in vitro drug release profiles of all the three kinds of nanoparticles showed a sustained release behavior and the release rate of OC-NPs was the fastest. Moreover, compared with NC-NPs and NOC-NPs, OC-NPs exhibited more cellular accumulation in the human gastric carcinoma cells (SGC 7901) as quantitatively determined by the flow cytometry and also much stronger cytotoxicity against these cells. Accordingly, our results showed that drug-loaded nanoparticles formed by different CMCs have dissimilar physiochemical characteristics which subsequently influence their therapeutic effects. We suggest that OC-based nanoparticle is a more desirable anti-tumor drug delivery system than NC-NP and NOC-NP.

Rapana venosa (Rv), an important marine snail, demonstrates an increasing nutritional and economic importance. However, there is still limited information available on their nutritional composition. The present study highlights and provides new information on the proximate composition, amino acid and fatty acid profiles of different body parts of Rv, aiming for its better application and research.; Results: The operculum contained a high amount of protein and flavor amino acids. The edible tissues, including meat and visceral mass, were valuable sources of essential amino acids (EAA) apart from methionine and cysteine. In addition, the meat contained high amount of taurine. Fatty acid analysis indicated that the edible tissues contained high amounts of ω3 fatty acids, especially eicosapentaenoic acid (EPA) (C20:5ω3) and docosahexaenoic acid (DHA) (C22:6ω3), and had a low ω6/ω3 fatty acid ratio. Interestingly, significantly higher concentrations of most nutritional elements such as fat, EAA, EPA and DHA, were found in the visceral mass compared to those in the meat.; Conclusion: The operculum of Rv may became a very interesting source for some protein and flavor peptide development, and the edible parts of Rv may be utilized for special dietary applications requiring high amounts of taurine, EPA, DHA and a lower ω6/ω3 fatty acid ratio. © 2017 Society of Chemical Industry.; © 2017 Society of Chemical Industry.

Three kinds of chitooligosaccharides were prepared using traditional (ZCOS), microwave irradiation (WCOS), and enzymatic hydrolysis (YCOS), and their monomer compositions and in vitro and in vivo immunomodulatory activities were determined. ZCOS was mainly comprised of disaccharides and trisaccharides; WCOS was mainly comprised of disaccharides to hexasaccharides with or without acetyl groups; and YCOS was mainly comprised of trisaccharides to pentasaccharides without acetyl groups. Differences in monomer composition and acetyl groups affected their immunomodulatory activities. Chitooligosaccharides degraded by different methods: all significantly stimulated the immune system by acting through cellular and humoral immunities. WCOS, obtained by microwave irradiation, had the best immunomodulatory activity. It significantly increased the spleen index and significantly stimulated delayed-type hypersensitivity compared the other two chitooligosaccharides. These activities might have been the result of the hexamer and acetyl groups of WCOS.

Seven chitooligomers (COSs) with determined degrees of polymerization (DPs) (chitotetraose to chitooctaose, DP 8-10, DP 10-12) and a heterogeneous COS with various DPs were first applied to explore the relationship between the DP of COSs and their effect on the growth of wheat seedlings under salt stress. The results showed that COS could promote the growth of wheat seedlings under salt stress. Moreover, chitohexaose, chitoheptaose, and chitooctaose exhibited stronger activity compared with other COS samples, which suggested that their activity had a close relationship with the DP. After 10 days of treatment with chitohexaose, chitoheptaose, and chitooctaose, the photosynthetic parameters were obviously improved. The soluble sugar and proline contents were improved by 26.7-53.3 and 43.6-70.2%, respectively, whereas the concentration of malondialdehyde (MDA) was reduced by 36.8-49.6%. In addition, the antioxidant enzyme activities were clearly activated. At the molecular level, the results revealed that they could obviously induce the expression of Na

Marine bioactive peptides, as a source of unique bioactive compounds, are the focus of current research. They exert various biological roles, some of the most crucial of which are antioxidant activity, antimicrobial activity, anticancer activity, antihypertensive activity, anti-inflammatory activity, and so forth, and specific characteristics of the bioactivities are described. This review also describes various manufacturing techniques for marine bioactive peptides using organic synthesis, microwave assisted extraction, chemical hydrolysis, and enzymes hydrolysis. Finally, purification of marine bioactive peptides is described, including gel or size exclusion chromatography, ion-exchange column chromatography, and reversed-phase high-performance liquid chromatography, which are aimed at finding a fast, simple, and effective method to obtain the target peptides.

Chitin was extracted from shrimp shells powders (SSP) by successive two-step fermentation. The best microorganisms Lactobacillus rhamnoides and Bacillus amyloliquefaciens (BA01) for demineralization (DM) and deproteinization (DP) were obtained and the optimal fermentation conditions for two-step fermentation were established. Firstly, we determined the cultured conditions (inoculum level 4%, initial pH 6.5, cultured temperature 37 °C, glucose concentration 5%, cultured time 48 h) of Lactobacillus rhamnoides and the organic acid quantities and types of fermentation broth of Lactobacillus rhamnoides. Under the conditions, the pH of fermentation broth was 3.4, the DM efficiency was 97.5% and the ash in the final residue was 1.2%, and the main organic acid was lactic acid. Secondly, the optimal cultured conditions of BA01 were inoculum level 6%, initial pH 6.5, cultured temperature 37 °C, glucose concentration 4%, and cultured time 84 h. Under the conditions, the protease activity of fermentation broth was 701.3 U/mL, the DP efficiency was 96.8%, the protein in the final residue was 1.5%, and the chitin yield was 19.6%. In addition, the chitin obtained by fermentation was compared with the commercial chitin using scanning Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Solid-state 13C CP/MAS-NMR spectra, and Scanning electron microscope (SEM). The results showed the chitin obtained by fermentation maintains the excellent physicochemical and structural properties of commercial chitin. Moreover, in order to make full use of shrimp and crab shells resources, the amino acid composition of fermentation broth was detected. The results showed that the fermentation broth had high nutritional value and could be used as a health nutrient in animal feed, even food.

The aim of this study was to isolate and purify antioxidative peptides from Pacific herring (Clupea pallasii) protein. Five enzymes (pepsin, trypsin, papain, flavourzyme, and neutrase) were used for protein hydrolysis, and Pacific herring protein hydrolysates (PHPH) were separated by ultrafiltration. The fraction with the molecular weight below 3500 Da exhibited the highest in vitro antioxidant activities and cellular antioxidant activity. The PHPH was isolated and purified by consecutive chromatographic methods including gel filtration chromatography and reverse high-performance liquid chromatography (RP-HPLC). The purified antioxidant peptides were identified as Leu-His-Asp-Glu-Leu-Thr (MW = 726.35 Da) and Lys-Glu-Glu-Lys-Phe-Glu (MW = 808.40 Da), and the IC50 values of cellular antioxidant activity were 1.19 &plusmn, 0.05 mg/mL and 1.04 &plusmn, 0.06 mg/mL. The results demonstrate that is possible to produce natural antioxidative peptides from Pacific herring protein via enzymatic hydrolysis and purification.

Chitosan has attracted considerable attention as an anti-tumor drug carrier material in recent years, which is due to its biocompatibility and biodegradability, as well as the simple and mild preparing techniques of drug-loaded nanoparticles. Chitosan-based nanoparticles can deliver various anti-tumor agents to specific tumor tissues by passive and active targeting mechanisms, including traditional chemotherapeutic agents, DNA or siRNA, proteins, photosensitizers and so on. In this review, we summarized the factors affecting the anti-tumor efficacy of chitosan-based nanoparticles, to aid exploring the function-structure relationship. The recent studies on chitosan-based nanoparticles for oncotherapy were highlighted, including their structures, properties and pharmacological effects. Finally, we offered our perspectives on the challenges and future development of this area.

Encapsulation of water-soluble nitrogen fertilizers by membranes can be used to control the release of nutrients to maximize the fertilization effect and reduce environmental pollution. In this research, we formulated a new double-coated controlled-release fertilizer (CRF) by using food-grade microcrystalline wax (MW) and marine polysaccharide derivatives (calcium alginate and chitosan-glutaraldehyde copolymer). The pellets of water-soluble nitrogen fertilizer were coated with the marine polysaccharide derivatives and MW. A convenient and eco-friendly method was used to prepare the CRF. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize the morphology and composition of the products. The nitrogen-release properties were determined in water using UV-Vis spectrophotometry. The controlled-release properties of the fertilizer were improved dramatically after coating with MW and the marine polysaccharide derivatives. The results show that the double-coated CRFs can release nitrogen in a controlled manner, have excellent controlled-release features, and meet the European Standard for CRFs.

In this study, three hymexazol-linked chitosan derivatives (HML-CS) were synthesized and their structures confirmed by Fourier transform infrared and elemental analysis. Linkage ratios were measured by high performance liquid chromatography. The derivatives’ antifungal activity against the plant pathogenic fungi Rhizoctonia solani CGMCC 3.28 and Gibberella zeae CGMCC 3.42 were investigated at concentrations of 100, 200, and 400 mg/L. These HML-CS derivatives exhibited stronger antifungal activity than CS alone. HML-CS-1 showed the best antifungal activity against G. zeae, whose antifungal index was 65.9% at 400 mg/L, and also showed the best antifungal activity against R. solani, whose antifungal index was 52.7% at 400 mg/L. This conjugation of CS and HML suggested the presence of synergistic effects between the moieties and indicated that these derivatives possessed great potential as novel fungicides and require further research for the development of applications in crop protection.

Sea cucumber is a traditional nutritional food and medicinal resource with many bioactive components in China. Holothuria fuscogliva is a big sea cucumber with a rich of bioactive polysaccharides. To investigate the bioactivities of the polysaccharides from sea cucumber H. fuscogliva, we prepared the sulfated polysaccharides (HfP) from sea cucumber H. fuscogliva using a protease hydrolysis method. Antioxidant activities of HfP were investigated, including hydroxyl radical scavenging activity and superoxide radical scavenging activity. And, the anticoagulant activities of HfP were studied, including the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT). The average molecular weight was 1 867.1 Da, with a sulfate content of 20.7%. In addition, the molar ratio of monosaccharide composition of HfP was Man: Rha: Glc A: Glc: Gal: Xyl: Fuc=0.083 6: 0.437: 0.134: 0:1.182: 0.748: 1. It had a strong antioxidant activity, the hydroxyl and superoxide radical scavenging activity EC50 of HfP was 3.74 and 0.037 mg/mL, respectively. It also showed a good anticoagulant activity in our study. The APTT of HfP was much higher than that of heparin sodium, and the PT and TT of HfP was close to that of heparin sodium at a low concentration. Therefore, HfP shows a good antioxidant and anticoagulant activity and it may become a potential candidate of the natural antioxidant and anticoagulant and will have a good application future in health product or medicine industry.

In this study, sulfated chitooligosaccharide (SCOS) was applied to wheat seedlings to investigate its effect on the plants' defense response under salt stress. The antioxidant enzyme activities, chlorophyll contents, and fluorescence characters of wheat seedlings were determined at a certain time. The results showed that treatment with exogenous SCOS could decrease the content of malondialdehyde, increase the chlorophyll contents, and modulate fluorescence characters in wheat seedlings under salt stress. In addition, SCOS was able to regulate the activities of antioxidant enzymes containing superoxide dismutase, catalase, peroxidase, ascorbate peroxidase, glutathione reductase, and dehydroascorbate reductase. Similarly, the mRNA expression levels of several antioxidant enzymes were efficiently modulated by SCOS. The results indicated that SCOS could alleviate the damage of salt stress by adjusting the antioxidant enzyme activities of plant. The effect of SCOS on the photochemical efficiency of wheat seedlings was associated with its enhanced capacity for antioxidant enzymes, which prevented structure degradation of the photosynthetic apparatus under NaCl stress. Furthermore, the effective activities of alleviating salt stress indicated the activities of SCOS were closely related with the sulfate group.

This study evaluated the protective effects of γ-aminobutyric acid (GABA), a non-protein amino acid and anti-oxidant, against fluoride-induced hypothyroidism in mice.Light microscope sample preparation technique and TEM sample preparation technique were used to assay thyroid microstructure and ultrastructure; enzyme immunoassay method was used to assay hormone and protein levels; immunohistochemical staining method was used to assay apoptosis of thyroid follicular epithelium cells.Subacute injection of sodium fluoride (NaF) decreased blood T4, T3 and thyroid hormone-binding globulin (TBG) levels to 33.98 μg/l, 3 2.8 ng/ml and 11.67 ng/ml, respectively. In addition, fluoride intoxication induced structural abnormalities in thyroid follicles. Our results showed that treatment of fluoride-exposed mice with GABA appreciably decreased metabolic toxicity induced by fluoride and restored the microstructural and ultrastructural organisation of the thyroid gland towards normalcy. Compared with the negative control group, GABA treatment groups showed significantly upregulated T4, T3 and TBG levels (42.34 μg/l, 6.54 ng/ml and 18.78 ng/ml, respectively; P0.05), properly increased TSH level and apoptosis inhibition in thyroid follicular epithelial cells.To the best of our knowledge, this is the first study to establish the therapeutic efficacy of GABA as a natural antioxidant in inducing thyroprotection against fluoride-induced toxicity.

Cyanea nozakii Kishinouy e (C. nozakii), a giant cnidarian of the class Scyphomedusae, order Semaeostomeae and family Cyaneidae, is widely distributed in the East China Sea, the Yellow Sea and the Bohai Sea, and is abundant from late summer to early autumn. Venom produced by C. nozakii during mass agglomerations can contaminate seawater resulting in death of the halobios and seriously damage commercial fisheries. Swimmers and fishermen commonly suff er painful stings from this jellyfish, resulting in local edema, tingling, breathing difficulties, depressed blood pressure and even death. Such effects arise from the complex mixture of biologically active molecules that make up jellyfish venom. In the present study, the hemolytic activity of venom from tentacles of C. nozakii and factors aff ecting its activity were assayed. The HU50 ( defined as the amount of protein required to lyse 50 % of erythrocytes) of the venom against dove and chicken erythrocytes was 34 and 59 μg/mL, respectively. Carboxylmethyl chitosan and glycerol could increase hemolytic activity at concentrations greater than 0.06% and 0.2 mol/L, respectively.

Beta-chitosan has a parallel structure, which differs from alpha-chitosan's antiparallel structure while producing different properties and difficulties. In this paper, we prepared the beta-chitosan through acid and alkali methods and the resultant material was characterized by elemental analysis, FT-IR, HPLC, XRD, NMR and AFS. To increase the solubility and biological activity of the beta-chitosan, we degraded it through microwave-assisted process. After characterization, we determined that the chitosan had not changed its configuration during the reaction with H2O2 under microwave irradiation. The inhibitory activity of the degraded chitosan for Newcastle disease was revealed by a hemagglutination test and RT-PCR. The yield of the beta-chitosan was approximately 30%, and its molecular weight can be degraded to 1000 to 10,000g/mol. Moreover, the degraded β-chitosan has higher antiviral activity, reducing the hemagglutination titre to zero, compared with alpha-chitosan. Therefore, beta-chitosan has good development prospects during the development of veterinary drugs for Newcastle disease.

Oyster (Crassostrea talienwhanensis) protein was hydrolyzed by trypsin to produce peptides with different response values, and response surface methodology (RSM) was applied to optimize the hydrolysis conditions. The highest degree of hydrolysis (DH) of the oyster peptide (OP) was obtained at an enzyme concentration of 1593.2 U/g, a pH of 8.2, a hydrolysis temperature of 40.1 &deg, C, a hydrolysis time of 6.0 h, and a water/material ratio of 8.2. The greatest hydroxyl-radical-scavenging activity of OP was obtained at an enzyme concentration of 1546.3 U/g, a pH of 9.0, a hydrolysis temperature of 50.2 &deg, C, a hydrolysis time of 5.1 h, and a water/material ratio of 5.6. The largest branched-chain amino acid (BCAA) content of OP was obtained at an enzyme concentration of 1323.8 U/g, a pH of 8.3, a hydrolysis temperature of 41.7 &deg, C, a hydrolysis time of 6.7 h, and a water/material ratio of 4.8. The three experimental values were significantly in agreement with the predicted values within the 95% confidence interval. Furthermore, ultrafiltration and chromatographic methods were used to purify the OP, and 13 peptides that were rich in Lys, Arg, His, and Thr were identified by LC-MS/MS. The results of this study offer different optimum hydrolysis conditions to produce target peptides from oyster protein by using RSM, and this study provide a theoretical basis for the high-value utilization of oyster protein.

Novel Co4S3/Co3O4 composite nanotubes were first time successfully synthesized through the control of Na2S treatment of Co(CO3)0.35Cl0.20(OH)1.10 precursor and testified to having both oxidase-like and peroxidase-like catalytic activities. Through nanoscale Kirkendall effect, acicular precursor was vulcanized to form Co4S3/Co3O4 nanotubes (NTs). Co4S3/Co3O4 NTs exhibit great properties such as smaller Km and higher Vmax than natural horseradish peroxidase, favorable selectivity and ideal stability. Co4S3/Co3O4 NTs with promising biocompatibility can realize spectral sterilization towards Escherichia coli and Staphylococcus sciuri in the presence of low level H2O2. It turned to be that superoxide anion radical catalyzed by Co4S3/Co3O4 NTs not only oxidizes 3, 3′, 5, 5′-tetramethylbenzidine in the catalytic process but also eliminates gram-bacteria during sterilization. The successful synthesis of biofunctional Co4S3/Co3O4 NTs can serve as significant applications of new energy and environmental catalysis.

Plant root-knot nematode disease is a great agricultural problem and commercially available nematicides have the disadvantages of high toxicity and limited usage, thus, it is urgent to develop new nematicides derived from nature substances. In this study, a novel fluorinated derivative was synthesized by modifying chitosan oligosaccharide (COS) using the strategy of multiple functions. The derivatives were characterized by FTIR, NMR, elemental analysis, and TG/DTG. The activity assays show that the derivatives can effectively kill the second instar larvae of Meloidogyne incognita in vitro, among them, chitosan-thiadiazole-trifluorobutene (COSSZFB) perform high eggs hatching inhibitory activity. The derivatives can regulate plant growth (photosynthetic pigment), improve immunity (chitinase and &beta, 1,3-glucanase), and show low cytotoxicity and phytotoxicity. According to the multi-functional activity, the derivatives exhibit a good control effect on plant root-knot nematode disease in vivo. The results demonstrate that the COS derivatives (especially fluorinated derivative) perform multiple activities and show the potential to be further evaluated as nematicides.

Chitosan (CS) and its water-soluble derivatives, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) and sulfated chitosan (SCS), were used as adjuvants of inactivated Newcastle disease (ND) vaccine. First, NDV-loaded and blank CS, HACC/CS and SCS nanoparticles were prepared. The particle sizes were respectively 343.43 ± 4.12, 320.03 ± 0.84, 156.2 ± 9.29 nm and the zeta potentials were respectively +19.67 ± 0.58, +18.3 ± 0.5, −17.8 ± 2.65 mV under the optimal conditions. Then chickens were immunized with nanoparticles or commercial inactivated oil emulsion vaccine. After immunization, the humoral immunity levels of the chickens were evaluated. The cellular immunity levels were determined by the quantification of cytokines, lymphocyte proliferation assay, the percentages of CD4+ and CD8+ T lymphocytes. Finally, the chickens were challenged with highly virulent virus. The results demonstrated that the humoral immunity levels in NDV-loaded CS and HACC/CS nanoparticles groups were lower than commercial vaccine but the cellular immunity levels are better. Moreover, the prevention effects of NDV-loaded CS and HACC/CS nanoparticles against highly virulent NDV are comparable to commercial vaccine. Our study provides the basis of developing HACC and CS as effective vaccine adjuvants.

Plant-parasitic nematodes cause substantial crop losses annually; however, current nematicides are environmentally unfriendly and highly toxic to nontarget organisms. The development of green efficient nematicides from multifunctional natural bioactive substances such as chitin oligosaccharide (COS) is promising. In this paper, COS dithiocarbamate derivatives (COSDTC, COSDTA, COSDTB) were synthesized to increase nematicidal activity (against Meloidogyne incognita), and their structures were characterized by FTIR, NMR, TGA/DTG and elemental analysis. Furthermore, the nematicidal activities, egg hatching inhibitory activities, plant growth adjustment abilities, cytotoxicity and phytotoxicity of the derivatives were evaluated. The primary mechanism was assessed by heavy metal ion absorption and GSH-binding assays. The results showed COS dithiocarbamate derivatives could possess multiple efficacies, including high nematicidal activities and egg hatching inhibitory activities, plant growth regulating effects, low cell toxicities and phytotoxicities. Additionally, it was inferred that nematicidal activity may be correlated with GSH-binding activity but not heavy metal ion complexation. COS modification has immense potential for controlling plant-parasitic nematodes.

Three trials were conducted to comprehensively evaluate the application of chitooligosaccharides (COSs) different dosages, molecular weights (MW) and degrees of deacetylation (DD) as a feed additive for Pacific white shrimp (Litopenaeus vannamei). In trial 1, COSs (3 KDa and 85% DD) at four different dosages (0.05%, 0.1%, 0.15% and 0.2%) were added to feed to investigate the appropriate dosages. The survival ratio (SR) of the shrimps was not significantly different (P 0.05) between the control and treatment groups. The shrimps fed with 0.1% COSs supplementation exhibited the highest wet body weight (FBW), specific growth ratio (SGR), and weight gain (WG) and the lowest feed conversion ratio (FCR). In trial 2, COSs with different MW (85% DD and 0.1% dosage) were tested. Except for the group treated with the 12 KDa COSs, all shrimps fed with COSs had remarkably higher (P 0.05) FBW, WG, and SGR and lower FCR (P 0.05) than the control group, and shrimps fed with the 1 KDa COSs showed most positive effects. In trial 3, COSs with different DD (MW of 1 KDa and 0.1% dosage) were further studied. The different DD were DD5, DD25, DD50, DD75, and DD95. Shrimps fed COSs-supplemented diets of DD75 or DD95 exhibited higher (P 0.05) FBW, WG and SGR and lower FCR than the other groups. The DD95 group had the highest FBW, WG and SGR and the lowest FCR, but there were no significant differences (P 0.05) between the DD75 and DD95 groups. Moreover, for COSs supplementation, especially for the DD75 and DD95 groups, the antioxidant parameters were significantly different from those of the other groups. Furthermore, groups fed diets with COSs supplementation had higher (P 0.05) trypsin activity than those fed control diets. In addition, immune and antioxidant gene expression and the morphology of the hepatopancreas were affected by the DD of COSs. Therefore, the additive dosages, molecular weights and degrees of deacetylation of COSs significantly affected the growth performance of the shrimps; therefore, it is particularly important to determine the optimum parameters of COSs.

Hydroxypropyltrimethyl ammonium chloride chitosan (HACC) is a water-soluble derivative of chitosan. To investigate the immunostimulatory effects of HACC, quaternized chitosans with different molecular weights were prepared and their effects on RAW 264.7 macrophages were compared. The results showed that HACC promoted nitric oxide (NO) production in a molecular weight- and dose-dependent manner. Lower molecular weight HACC was more active in promoting NO production. Furthermore, flow cytometry analysis showed that HACC significantly promoted the production of interleukin-6 and tumor necrosis factor-α. These results were further demonstrated by quantitive real-time reverse transcription polymerase chain reaction and western blot analysis. Moreover, western blotting revealed that HACC induced the phosphorylation of extracellular signal-regulated kinase, c-Jun N-terminal kinase, p38, and signal transducer and activator of transcription (STAT) proteins. In conclusion, HACC activated RAW 264.7 cells through the mitogen-activated protein kinases and Janus kinase/STAT pathways.

This study reports the preparation, purification and identification of an antioxidative peptide from mackerel (

In this study, 3-methyl-1,2,4-triazolyl chitosan (MTACS) and 3-chloromethyl-1,2,4-triazolyl chitosan (CMTACS) were prepared via cyclization of acyl thiourea chitosan (TUCS). Their structures were confirmed by FT-IR, 1H-NMR, elemental analysis, DSC, XRD, and SEM. The conformations were predicted using the Gaussian 09 program. Additionally, the antifungal properties of MTACS and CMTACS against Stemphylium solani weber (S. solani), Alternaria porri (A. porri), and Gloeosporium theae-sinensis (G. theae-sinensis) were assayed in vitro and ranged from 250 μg/mL to 1000 μg/mL. The results showed that MTACS and CMTACS exhibited enhanced inhibitory effect on the selected fungi compared to the original chitosan and TUCS. In particular, they displayed better antifungal activities against A. porri and G. theae-sinensis than that of the positive control, Triadimefon. The findings described here may lead to them being used as antifungal agents for crop protection.

A new superabsorbent polymer was synthesized using amino ethyl chitosan and an acrylic acid by a free radical polymerization. The chemical structure of the superabsorbent polymer was characterized using FTIR, TGA, XRD and solid-state 13C NMR. The results revealed that the acrylic acid was successfully grafted onto the amino ethyl chitosan backbone. As revealed by SEM, a surface with homogeneous and interconnected pore structure was obtained. The influences of different factors (e.g., the initiator, cross-linker and monomer) on the water absorbency of the superabsorbent polymers were investigated. The results indicated that the superabsorbent polymers have a good swelling ability, water evaporation rate, excellent salt tolerance and pH sensitivity. The new superabsorbent polymers have potential as a water-retaining agent.

Mackerel (Pneumatophorus japonicus) viscera contain large amount of protein. We used five proteases to hydrolyze the viscera, and the hydrolysate treated by neutrase exhibited the highest nitrogen recovery (NR). Then we optimized the preparation conditions for mackerel viscera hydrolysate (MVH) by response surface methodology and investigated the antioxidant activity of MVH. The optimal conditions were as follows: enzyme concentration of 1,762.87 U/g, pH of 6.76, temperature of 43.75 °C, extraction time of 6.0 h and water/material ratio of 20.37 (v/w), and the maximum NR was 37.84%. Furthermore, the molecular weight distribution of MVH was almost below 3,000 Da determined by TSK G2000 SWXL gel filtration chromatography, and the MVH exhibited good antioxidant activities in various in vitro assays, including DPPH radical, hydroxyl radical and superoxide anion scavenging activities, reducing power and similar effectivelness as butylated hydroxytoluene and Vitamin E to inhibit lipid peroxidation. The results suggested that MVH could be used as a potential source of antioxidant peptide in food industries.